Back in the day, hundreds of letters, claiming to have been written by ‘Jack the Ripper; were sent to the media and the London police following the brutal Whitechapel murders of 1888.
The letters have long remained a mystery with many suspecting that they might have been written by journalists who wanted to sell more newspapers.
However, scientists have recently provided new evidence that suggests that the letters were, in fact, fakes.
The study focused on the 'Dear Boss' letter, in which the name Jack the Ripper appears for the first time, and the 'Saucy Jacky' postcard.
It found similar linguistic constructions in both letters, such as the phrasal verb 'to keep back', as well as similarities in the handwriting.
Both letters also have a likeness to a third text long thought to be a hoax, known as the 'Moab and Midian' letter.
According to history, Jack the Ripper is thought to have killed at least five young women in Whitechapel, east London, over the course of three months, but was never caught.
The police started to publish letters allegedly from Jack the Ripper after receiving the first four, which encouraged hoaxers to send copycat letters claiming to be written by the killer.
The study saw, Dr Andrea Nini, from the University of Manchester, undertake a 'cluster analysis' of 209 letters linked to the Ripper, studying similarities in the documents' text.
The 'Dear Boss' letter and 'Saucy Jacky' postcard stood out due to the striking similarities.
Similarities between the two texts include the use of the phrasal verb 'to keep back' mean 'to withhold'.
The Dear Boss letter, scrawled in red ink, was received by the Central News Agency in London on September 27, 1888, and forwarded to Scotland Yard.
'Saucy Jacky' was used as a reference to the killer in a postcard received by the Central News Agency on October 1, 1888.
Using modern linguistic techniques to analyse the letters, Dr Nini uncovered certain shared distinctive linguistic constructions in the two early texts and came to the conclusion that there is very strong linguistic evidence that these two texts were written by the same person.
Dr Nini also found evidence that a link exists between these letters and another of the key texts in the case, the 'Moab and Midian' letter.
Many people believe the text was a hoax created by the Central News Agency.
According to the study, the study doesn't identify the killer, or the author of the two letters, but it does seem to back up the journalist theory.